import 'package:flutter/material.dart';
import 'package:english_words/english_words.dart';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Welcome to Flutter',
      home: new RandomWords(),
      theme: new ThemeData(
        primaryColor: Colors.cyan,
      ),
    );
  }
}

class RandomWords extends StatefulWidget {
  @override
  createState() => new RandomWordsState();
}

class RandomWordsState extends State<RandomWords> {
  final _suggestions = <WordPair>[];//list
  final _saved = new Set<WordPair>(); //set不允许有重复值
  final _biggerFont = const TextStyle(fontSize: 18.0);


  @override
  Widget build(BuildContext context) {
    /*final wordPair = new WordPair.random();
    return new Text(wordPair.asPascalCase);*/

    return new Scaffold(
      appBar: new AppBar(
          title: new Text('startup name gemerator'),
          actions: <Widget>[new IconButton(icon: new Icon(Icons.list), onPressed: _pushSaved)]),
      body: _buildSuggestions(),
    );
  }

  Widget _buildSuggestions() {//listView
    return new ListView.builder(
        padding: const EdgeInsets.all(16.0),
        itemBuilder: (context, i) {
          if (i.isOdd) return new Divider();

          final index = i ~/ 2;
          if (index >= _suggestions.length) {
            _suggestions.addAll(generateWordPairs().take(10));
          }
          return _buildRow(_suggestions[index]);
        });
  }

  Widget _buildRow(WordPair pair) {//item样式
    final alreadySaved = _saved.contains(pair);
    return new ListTile(
      title: new Text(
        pair.asPascalCase,
        style: _biggerFont,
      ),
      trailing: new Icon(
        alreadySaved ? Icons.favorite : Icons.favorite_border,
        color: alreadySaved ? Colors.red : null,
      ),
      onTap: () {
        setState(() {
          if (alreadySaved) {
            _saved.remove(pair);
          } else {
            _saved.add(pair);
          }
        });
      },
    );
  }
  
  void _pushSaved(){
    Navigator.of(context).push(
      new MaterialPageRoute(builder: (context){
        final tiles=_saved.map(
            (pair){
              return new ListTile(
                title: new Text(
                  pair.asPascalCase,
                  style: _biggerFont,
                  textAlign:TextAlign.center ,
                ),
              );
            },
        );

        final divided=ListTile.divideTiles(
            context:context,
            tiles: tiles,
        ).toList();

        return new Scaffold(
          appBar: new AppBar(
            title: new Text("saved suggestions"),
          ),
          body: new ListView(children: divided,),
        );
      })
    );
        
  }
}


